转载请说明原出处，谢谢：http://blog.csdn.net/zhuhongshu/article/details/42580877
之前我写的程序使用阴影时，一直是使用codeproject网站上的WndShadow类，并且把它当作单独的模块来使用，后来觉得使用阴影的情况非常多，所以今天就把这个类改写了一下，让他融入到duilib，并且可以直接使用xml来描述阴影，不需要写任何c++代码。
以前的WndShadow类是用算法来计算阴影，灵活性很大，但是缺点就是效果不够理想，所以我另外给他附加了使用图片素材来贴阴影的功能。最终的新类名为CShadowUI。这个类可以单独使用，我把他集成到了自己的库里。为了融合到Duilib我修改了UiLib.h文件、UIDlgBuilder.cpp文件、UIManager.h文件、UIManager.cpp文件。
先贴两张效果图，以下是素材阴影和算法阴影的效果图：
通过设置xml的Window标签可以添加阴影，阴影的xml属性描述如下：
<Attribute name="showshadow" default="false" type="BOOL" comment="是否启用窗体阴影"/>
<Attribute name="shadowimage" default="" type="STRING" comment="阴影图片，使用此属性后自动屏蔽算法阴影(不支持source等属性设置)"/>
<Attribute name="shadowcorner" default="0,0,0,0" type="RECT" comment="图片阴影的九宫格描述"/>
<Attribute name="shadowsize" default="0" type="BYTE" comment="算法阴影的宽度(-20到20)"/>
<Attribute name="shadowsharpness" default="255" type="BYTE" comment="算法阴影的锐度"/>
<Attribute name="shadowdarkness" default="255" type="BYTE" comment="算法阴影的深度(相当于透明度)"/>
<Attribute name="shadowpositon" default="0,0" type="SIZE" comment="算法阴影的偏移量"/>
<Attribute name="shadowcolor" default="0x000000" type="DWORD" comment="算法阴影的颜色，RGB格式，不支持透明度，使用shadowdarkness设置透明度"/>
前面的两个效果图的对应xml描述如下：
<!-- 图片阴影 -->
<Window size="840,600" sizebox="4,4,4,4" caption="0,0,0,75" mininfo="840,600" showshadow="true" shadowimage="shadow.png" shadowcorner="23,13,23,33">
<!-- 算法阴影 -->
<Window size="840,600" sizebox="4,4,4,4" caption="0,0,0,75" mininfo="840,600" showshadow="true" shadowsize="5" shadowpositon="1,1" shadowcolor="#333333">
源码：
UIShadow.h源码为：
// WndShadow.h : header file
//
// Version 0.1
//
// Copyright (c) 2006 Perry Zhu, All Rights Reserved.
//
// mailto:perry@live.com
//
//
// This source file may be redistributed unmodified by any means PROVIDING
// it is NOT sold for profit without the authors expressed written
// consent, and providing that this notice and the author's name and all
// copyright notices remain intact. This software is by no means to be
// included as part of any third party components library, or as part any
// development solution that offers MFC extensions that are sold for profit.
//
// If the source code is used in any commercial applications then a statement
// along the lines of:
//
// "Portions Copyright (c) 2006 Perry Zhu" must be included in the "Startup
// Banner", "About Box" or "Printed Documentation". This software is provided
// "as is" without express or implied warranty. Use it at your own risk! The
// author accepts no liability for any damage/loss of business that this
// product may cause.
//
/////////////////////////////////////////////////////////////////////////////
//**************************************************************************** /********************************************************************
created: 2015/01/09
filename: UIShadow.h
author: Redrain purpose: DuiLib阴影类，在原WndShadow类的基础上，增加了通过PNG图片设置阴影的功能，并且把代码与DuiLib融合
*********************************************************************/ #ifndef __UISHADOW_H__
#define __UISHADOW_H__ #pragma once
#include "map" namespace DuiLib
{
typedef BOOL (WINAPI *pfnUpdateLayeredWindow)(HWND hWnd, HDC hdcDst, POINT *pptDst,
SIZE *psize, HDC hdcSrc, POINT *pptSrc, COLORREF crKey,
BLENDFUNCTION *pblend, DWORD dwFlags); class UILIB_API CShadowUI
{
public:
friend class CPaintManagerUI; CShadowUI(void);
virtual ~CShadowUI(void); public:
// bShow为真时才会创建阴影
void ShowShadow(bool bShow);
bool IsShowShadow() const; // 算法阴影的函数
bool SetSize(int NewSize = 0);
bool SetSharpness(unsigned int NewSharpness = 5);
bool SetDarkness(unsigned int NewDarkness = 200);
bool SetPosition(int NewXOffset = 5, int NewYOffset = 5);
bool SetColor(COLORREF NewColor = 0); // 图片阴影的函数
bool SetImage(LPCTSTR szImage);
bool SetShadowCorner(RECT rcCorner); // 九宫格方式描述阴影 protected: // 初始化并注册阴影类
static bool Initialize(HINSTANCE hInstance); // 创建阴影窗体，由CPaintManagerUI自动调用
void Create(CPaintManagerUI* pPaintManager); // 子类化父窗体
static LRESULT CALLBACK ParentProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam); // 父窗体改变大小，移动，或者主动重绘阴影时调用
void Update(HWND hParent); // 通过算法计算阴影
void MakeShadow(UINT32 *pShadBits, HWND hParent, RECT *rcParent); // 计算alpha预乘值
inline DWORD PreMultiply(COLORREF cl, unsigned char nAlpha)
{
return (GetRValue(cl) * (DWORD)nAlpha / 255) |
(GetGValue(cl) * (DWORD)nAlpha / 255) << 8 |
(GetBValue(cl) * (DWORD)nAlpha / 255) << 16 ;
} protected:
enum ShadowStatus
{
SS_ENABLED = 1, // Shadow is enabled, if not, the following one is always false
SS_VISABLE = 1 << 1, // Shadow window is visible
SS_PARENTVISIBLE = 1<< 2 // Parent window is visible, if not, the above one is always false
}; // 保存已经附加的窗体句柄和与其关联的阴影类,方便在ParentProc()函数中通过句柄得到阴影类
static std::map<HWND, CShadowUI *> *s_Shadowmap;
static bool s_bHasInit; CPaintManagerUI *m_pManager; // 父窗体的CPaintManagerUI，用来获取素材资源和父窗体句柄
HWND m_hWnd; // 阴影窗体的句柄
LONG m_OriParentProc; // 子类化父窗体
BYTE m_Status;
bool m_bIsImageMode; // 是否为图片阴影模式
bool m_bIsShowShadow; // 是否要显示阴影 // 算法阴影成员变量
unsigned char m_nDarkness; // Darkness, transparency of blurred area
unsigned char m_nSharpness; // Sharpness, width of blurred border of shadow window
signed char m_nSize; // Shadow window size, relative to parent window size // The X and Y offsets of shadow window,
// relative to the parent window, at center of both windows (not top-left corner), signed
signed char m_nxOffset;
signed char m_nyOffset; // Restore last parent window size, used to determine the update strategy when parent window is resized
LPARAM m_WndSize; // Set this to true if the shadow should not be update until next WM_PAINT is received
bool m_bUpdate; COLORREF m_Color; // Color of shadow // 图片阴影成员变量
CDuiString m_sShadowImage;
RECT m_rcShadowCorner;
}; } #endif //__UISHADOW_H__
UIShadow.cpp源码为：
#include "StdAfx.h"
#include "UIShadow.h"
#include "math.h"
#include "crtdbg.h"
#include "Core/UIManager.h" namespace DuiLib
{ const TCHAR *strWndClassName = _T("PerryShadowWnd");
std::map<HWND, CShadowUI *>* CShadowUI::s_Shadowmap = new std::map<HWND, CShadowUI *>;
bool CShadowUI::s_bHasInit = FALSE; CShadowUI::CShadowUI(void)
: m_hWnd((HWND)NULL)
, m_OriParentProc(NULL)
, m_nDarkness(150)
, m_nSharpness(5)
, m_nSize(0)
, m_nxOffset(0)
, m_nyOffset(0)
, m_Color(RGB(0, 0, 0))
, m_WndSize(0)
, m_bUpdate(false)
, m_bIsImageMode(false)
, m_bIsShowShadow(false)
{
::ZeroMemory(&m_rcShadowCorner, sizeof(RECT));
} CShadowUI::~CShadowUI(void)
{
} bool CShadowUI::Initialize(HINSTANCE hInstance)
{
if (s_bHasInit)
return false; // Register window class for shadow window
WNDCLASSEX wcex; memset(&wcex, 0, sizeof(wcex)); wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = DefWindowProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = NULL;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = strWndClassName;
wcex.hIconSm = NULL; RegisterClassEx(&wcex); s_bHasInit = true;
return true;
} void CShadowUI::Create(CPaintManagerUI* pPaintManager)
{
if(!m_bIsShowShadow)
return; // Already initialized
_ASSERT(CPaintManagerUI::GetInstance() != INVALID_HANDLE_VALUE);
_ASSERT(pPaintManager != NULL);
m_pManager = pPaintManager;
HWND hParentWnd = m_pManager->GetPaintWindow();
// Add parent window - shadow pair to the map
_ASSERT(s_Shadowmap->find(hParentWnd) == s_Shadowmap->end()); // Only one shadow for each window
(*s_Shadowmap)[hParentWnd] = this; // Determine the initial show state of shadow according to parent window's state
LONG lParentStyle = GetWindowLong(hParentWnd, GWL_STYLE); // Create the shadow window
LONG styleValue = lParentStyle & WS_CAPTION;
m_hWnd = CreateWindowEx(WS_EX_LAYERED | WS_EX_TRANSPARENT, strWndClassName, NULL,
/*WS_VISIBLE | */styleValue | WS_POPUPWINDOW,
CW_USEDEFAULT, 0, 0, 0, hParentWnd, NULL, CPaintManagerUI::GetInstance(), NULL); if(!(WS_VISIBLE & lParentStyle)) // Parent invisible
m_Status = SS_ENABLED;
else if((WS_MAXIMIZE | WS_MINIMIZE) & lParentStyle) // Parent visible but does not need shadow
m_Status = SS_ENABLED | SS_PARENTVISIBLE;
else // Show the shadow
{
m_Status = SS_ENABLED | SS_VISABLE | SS_PARENTVISIBLE;
::ShowWindow(m_hWnd, SW_SHOWNA);
Update(hParentWnd);
} // Replace the original WndProc of parent window to steal messages
m_OriParentProc = GetWindowLong(hParentWnd, GWL_WNDPROC); #pragma warning(disable: 4311) // temporrarily disable the type_cast warning in Win32
SetWindowLong(hParentWnd, GWL_WNDPROC, (LONG)ParentProc);
#pragma warning(default: 4311) } LRESULT CALLBACK CShadowUI::ParentProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
_ASSERT(s_Shadowmap->find(hwnd) != s_Shadowmap->end()); // Shadow must have been attached CShadowUI *pThis = (*s_Shadowmap)[hwnd]; switch(uMsg)
{
case WM_MOVE:
if(pThis->m_Status & SS_VISABLE)
{
RECT WndRect;
GetWindowRect(hwnd, &WndRect);
if (pThis->m_bIsImageMode)
{
SetWindowPos(pThis->m_hWnd, 0,
WndRect.left - pThis->m_rcShadowCorner.left, WndRect.top - pThis->m_rcShadowCorner.top,
0, 0, SWP_NOSIZE | SWP_NOACTIVATE);
}
else
{
SetWindowPos(pThis->m_hWnd, 0,
WndRect.left + pThis->m_nxOffset - pThis->m_nSize, WndRect.top + pThis->m_nyOffset - pThis->m_nSize,
0, 0, SWP_NOSIZE | SWP_NOACTIVATE);
}
}
break; case WM_SIZE:
if(pThis->m_Status & SS_ENABLED)
{
if(SIZE_MAXIMIZED == wParam || SIZE_MINIMIZED == wParam)
{
::ShowWindow(pThis->m_hWnd, SW_HIDE);
pThis->m_Status &= ~SS_VISABLE;
}
else if(pThis->m_Status & SS_PARENTVISIBLE) // Parent maybe resized even if invisible
{
// Awful! It seems that if the window size was not decreased
// the window region would never be updated until WM_PAINT was sent.
// So do not Update() until next WM_PAINT is received in this case
if(LOWORD(lParam) > LOWORD(pThis->m_WndSize) || HIWORD(lParam) > HIWORD(pThis->m_WndSize))
pThis->m_bUpdate = true;
else
pThis->Update(hwnd);
if(!(pThis->m_Status & SS_VISABLE))
{
::ShowWindow(pThis->m_hWnd, SW_SHOWNA);
pThis->m_Status |= SS_VISABLE;
}
}
pThis->m_WndSize = lParam;
}
break; case WM_PAINT:
{
if(pThis->m_bUpdate)
{
pThis->Update(hwnd);
pThis->m_bUpdate = false;
}
//return hr;
break;
} // In some cases of sizing, the up-right corner of the parent window region would not be properly updated
// Update() again when sizing is finished
case WM_EXITSIZEMOVE:
if(pThis->m_Status & SS_VISABLE)
{
pThis->Update(hwnd);
}
break; case WM_SHOWWINDOW:
if(pThis->m_Status & SS_ENABLED)
{
if(!wParam) // the window is being hidden
{
::ShowWindow(pThis->m_hWnd, SW_HIDE);
pThis->m_Status &= ~(SS_VISABLE | SS_PARENTVISIBLE);
}
else if(!(pThis->m_Status & SS_PARENTVISIBLE))
{
//pThis->Update(hwnd);
pThis->m_bUpdate = true;
::ShowWindow(pThis->m_hWnd, SW_SHOWNA);
pThis->m_Status |= SS_VISABLE | SS_PARENTVISIBLE;
}
}
break; case WM_DESTROY:
DestroyWindow(pThis->m_hWnd); // Destroy the shadow
break; case WM_NCDESTROY:
s_Shadowmap->erase(hwnd); // Remove this window and shadow from the map
break; } #pragma warning(disable: 4312) // temporrarily disable the type_cast warning in Win32
// Call the default(original) window procedure for other messages or messages processed but not returned
return ((WNDPROC)pThis->m_OriParentProc)(hwnd, uMsg, wParam, lParam);
#pragma warning(default: 4312) } void CShadowUI::Update(HWND hParent)
{ RECT WndRect;
GetWindowRect(hParent, &WndRect);
int nShadWndWid;
int nShadWndHei;
if (m_bIsImageMode)
{
if(m_sShadowImage.IsEmpty())
return; nShadWndWid = WndRect.right - WndRect.left + m_rcShadowCorner.left + m_rcShadowCorner.right;
nShadWndHei = WndRect.bottom - WndRect.top + m_rcShadowCorner.top + m_rcShadowCorner.bottom;
}
else
{
nShadWndWid = WndRect.right - WndRect.left + m_nSize * 2;
nShadWndHei = WndRect.bottom - WndRect.top + m_nSize * 2;
} // Create the alpha blending bitmap
BITMAPINFO bmi; // bitmap header ZeroMemory(&bmi, sizeof(BITMAPINFO));
bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth = nShadWndWid;
bmi.bmiHeader.biHeight = nShadWndHei;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 32; // four 8-bit components
bmi.bmiHeader.biCompression = BI_RGB;
bmi.bmiHeader.biSizeImage = nShadWndWid * nShadWndHei * 4; BYTE *pvBits; // pointer to DIB section
HBITMAP hbitmap = CreateDIBSection(NULL, &bmi, DIB_RGB_COLORS, (void **)&pvBits, NULL, 0);
HDC hMemDC = CreateCompatibleDC(NULL);
HBITMAP hOriBmp = (HBITMAP)SelectObject(hMemDC, hbitmap); if (m_bIsImageMode)
{
RECT rcPaint = {0, 0, nShadWndWid, nShadWndHei}; const TImageInfo* data = m_pManager->GetImageEx((LPCTSTR)m_sShadowImage, NULL, 0); if( !data )
return; RECT rcBmpPart = {0};
rcBmpPart.right = data->nX;
rcBmpPart.bottom = data->nY; CRenderEngine::DrawImage(hMemDC, data->hBitmap, rcPaint, rcPaint, rcBmpPart, m_rcShadowCorner, data->alphaChannel, 0xFF, true, false, false); }
else
{
ZeroMemory(pvBits, bmi.bmiHeader.biSizeImage);
MakeShadow((UINT32 *)pvBits, hParent, &WndRect);
} POINT ptDst;
if (m_bIsImageMode)
{
ptDst.x = WndRect.left - m_rcShadowCorner.left;
ptDst.y = WndRect.top - m_rcShadowCorner.top;
}
else
{
ptDst.x = WndRect.left + m_nxOffset - m_nSize;
ptDst.y = WndRect.top + m_nyOffset - m_nSize;
} POINT ptSrc = {0, 0};
SIZE WndSize = {nShadWndWid, nShadWndHei};
BLENDFUNCTION blendPixelFunction= { AC_SRC_OVER, 0, 255, AC_SRC_ALPHA }; MoveWindow(m_hWnd, ptDst.x, ptDst.y, nShadWndWid, nShadWndHei, FALSE); BOOL bRet= ::UpdateLayeredWindow(m_hWnd, NULL, &ptDst, &WndSize, hMemDC,
&ptSrc, 0, &blendPixelFunction, ULW_ALPHA); _ASSERT(bRet); // something was wrong.... // Delete used resources
SelectObject(hMemDC, hOriBmp);
DeleteObject(hbitmap);
DeleteDC(hMemDC); } void CShadowUI::MakeShadow(UINT32 *pShadBits, HWND hParent, RECT *rcParent)
{
// The shadow algorithm:
// Get the region of parent window,
// Apply morphologic erosion to shrink it into the size (ShadowWndSize - Sharpness)
// Apply modified (with blur effect) morphologic dilation to make the blurred border
// The algorithm is optimized by assuming parent window is just "one piece" and without "wholes" on it // Get the region of parent window,
HRGN hParentRgn = CreateRectRgn(0, 0, 0, 0);
GetWindowRgn(hParent, hParentRgn); // Determine the Start and end point of each horizontal scan line
SIZE szParent = {rcParent->right - rcParent->left, rcParent->bottom - rcParent->top};
SIZE szShadow = {szParent.cx + 2 * m_nSize, szParent.cy + 2 * m_nSize};
// Extra 2 lines (set to be empty) in ptAnchors are used in dilation
int nAnchors = max(szParent.cy, szShadow.cy); // # of anchor points pares
int (*ptAnchors)[2] = new int[nAnchors + 2][2];
int (*ptAnchorsOri)[2] = new int[szParent.cy][2]; // anchor points, will not modify during erosion
ptAnchors[0][0] = szParent.cx;
ptAnchors[0][1] = 0;
ptAnchors[nAnchors + 1][0] = szParent.cx;
ptAnchors[nAnchors + 1][1] = 0;
if(m_nSize > 0)
{
// Put the parent window anchors at the center
for(int i = 0; i < m_nSize; i++)
{
ptAnchors[i + 1][0] = szParent.cx;
ptAnchors[i + 1][1] = 0;
ptAnchors[szShadow.cy - i][0] = szParent.cx;
ptAnchors[szShadow.cy - i][1] = 0;
}
ptAnchors += m_nSize;
}
for(int i = 0; i < szParent.cy; i++)
{
// find start point
int j;
for(j = 0; j < szParent.cx; j++)
{
if(PtInRegion(hParentRgn, j, i))
{
ptAnchors[i + 1][0] = j + m_nSize;
ptAnchorsOri[i][0] = j;
break;
}
} if(j >= szParent.cx) // Start point not found
{
ptAnchors[i + 1][0] = szParent.cx;
ptAnchorsOri[i][1] = 0;
ptAnchors[i + 1][0] = szParent.cx;
ptAnchorsOri[i][1] = 0;
}
else
{
// find end point
for(j = szParent.cx - 1; j >= ptAnchors[i + 1][0]; j--)
{
if(PtInRegion(hParentRgn, j, i))
{
ptAnchors[i + 1][1] = j + 1 + m_nSize;
ptAnchorsOri[i][1] = j + 1;
break;
}
}
}
} if(m_nSize > 0)
ptAnchors -= m_nSize; // Restore pos of ptAnchors for erosion
int (*ptAnchorsTmp)[2] = new int[nAnchors + 2][2]; // Store the result of erosion
// First and last line should be empty
ptAnchorsTmp[0][0] = szParent.cx;
ptAnchorsTmp[0][1] = 0;
ptAnchorsTmp[nAnchors + 1][0] = szParent.cx;
ptAnchorsTmp[nAnchors + 1][1] = 0;
int nEroTimes = 0;
// morphologic erosion
for(int i = 0; i < m_nSharpness - m_nSize; i++)
{
nEroTimes++;
//ptAnchorsTmp[1][0] = szParent.cx;
//ptAnchorsTmp[1][1] = 0;
//ptAnchorsTmp[szParent.cy + 1][0] = szParent.cx;
//ptAnchorsTmp[szParent.cy + 1][1] = 0;
for(int j = 1; j < nAnchors + 1; j++)
{
ptAnchorsTmp[j][0] = max(ptAnchors[j - 1][0], max(ptAnchors[j][0], ptAnchors[j + 1][0])) + 1;
ptAnchorsTmp[j][1] = min(ptAnchors[j - 1][1], min(ptAnchors[j][1], ptAnchors[j + 1][1])) - 1;
}
// Exchange ptAnchors and ptAnchorsTmp;
int (*ptAnchorsXange)[2] = ptAnchorsTmp;
ptAnchorsTmp = ptAnchors;
ptAnchors = ptAnchorsXange;
} // morphologic dilation
ptAnchors += (m_nSize < 0 ? -m_nSize : 0) + 1; // now coordinates in ptAnchors are same as in shadow window
// Generate the kernel
int nKernelSize = m_nSize > m_nSharpness ? m_nSize : m_nSharpness;
int nCenterSize = m_nSize > m_nSharpness ? (m_nSize - m_nSharpness) : 0;
UINT32 *pKernel = new UINT32[(2 * nKernelSize + 1) * (2 * nKernelSize + 1)];
UINT32 *pKernelIter = pKernel;
for(int i = 0; i <= 2 * nKernelSize; i++)
{
for(int j = 0; j <= 2 * nKernelSize; j++)
{
double dLength = sqrt((i - nKernelSize) * (i - nKernelSize) + (j - nKernelSize) * (double)(j - nKernelSize));
if(dLength < nCenterSize)
*pKernelIter = m_nDarkness << 24 | PreMultiply(m_Color, m_nDarkness);
else if(dLength <= nKernelSize)
{
UINT32 nFactor = ((UINT32)((1 - (dLength - nCenterSize) / (m_nSharpness + 1)) * m_nDarkness));
*pKernelIter = nFactor << 24 | PreMultiply(m_Color, nFactor);
}
else
*pKernelIter = 0;
//TRACE("%d ", *pKernelIter >> 24);
pKernelIter ++;
}
//TRACE("\n");
}
// Generate blurred border
for(int i = nKernelSize; i < szShadow.cy - nKernelSize; i++)
{
int j;
if(ptAnchors[i][0] < ptAnchors[i][1])
{ // Start of line
for(j = ptAnchors[i][0];
j < min(max(ptAnchors[i - 1][0], ptAnchors[i + 1][0]) + 1, ptAnchors[i][1]);
j++)
{
for(int k = 0; k <= 2 * nKernelSize; k++)
{
UINT32 *pPixel = pShadBits +
(szShadow.cy - i - 1 + nKernelSize - k) * szShadow.cx + j - nKernelSize;
UINT32 *pKernelPixel = pKernel + k * (2 * nKernelSize + 1);
for(int l = 0; l <= 2 * nKernelSize; l++)
{
if(*pPixel < *pKernelPixel)
*pPixel = *pKernelPixel;
pPixel++;
pKernelPixel++;
}
}
} // for() start of line // End of line
for(j = max(j, min(ptAnchors[i - 1][1], ptAnchors[i + 1][1]) - 1);
j < ptAnchors[i][1];
j++)
{
for(int k = 0; k <= 2 * nKernelSize; k++)
{
UINT32 *pPixel = pShadBits +
(szShadow.cy - i - 1 + nKernelSize - k) * szShadow.cx + j - nKernelSize;
UINT32 *pKernelPixel = pKernel + k * (2 * nKernelSize + 1);
for(int l = 0; l <= 2 * nKernelSize; l++)
{
if(*pPixel < *pKernelPixel)
*pPixel = *pKernelPixel;
pPixel++;
pKernelPixel++;
}
}
} // for() end of line }
} // for() Generate blurred border // Erase unwanted parts and complement missing
UINT32 clCenter = m_nDarkness << 24 | PreMultiply(m_Color, m_nDarkness);
for(int i = min(nKernelSize, max(m_nSize - m_nyOffset, 0));
i < max(szShadow.cy - nKernelSize, min(szParent.cy + m_nSize - m_nyOffset, szParent.cy + 2 * m_nSize));
i++)
{
UINT32 *pLine = pShadBits + (szShadow.cy - i - 1) * szShadow.cx;
if(i - m_nSize + m_nyOffset < 0 || i - m_nSize + m_nyOffset >= szParent.cy) // Line is not covered by parent window
{
for(int j = ptAnchors[i][0]; j < ptAnchors[i][1]; j++)
{
*(pLine + j) = clCenter;
}
}
else
{
for(int j = ptAnchors[i][0];
j < min(ptAnchorsOri[i - m_nSize + m_nyOffset][0] + m_nSize - m_nxOffset, ptAnchors[i][1]);
j++)
*(pLine + j) = clCenter;
for(int j = max(ptAnchorsOri[i - m_nSize + m_nyOffset][0] + m_nSize - m_nxOffset, 0);
j < min(ptAnchorsOri[i - m_nSize + m_nyOffset][1] + m_nSize - m_nxOffset, szShadow.cx);
j++)
*(pLine + j) = 0;
for(int j = max(ptAnchorsOri[i - m_nSize + m_nyOffset][1] + m_nSize - m_nxOffset, ptAnchors[i][0]);
j < ptAnchors[i][1];
j++)
*(pLine + j) = clCenter;
}
} // Delete used resources
delete[] (ptAnchors - (m_nSize < 0 ? -m_nSize : 0) - 1);
delete[] ptAnchorsTmp;
delete[] ptAnchorsOri;
delete[] pKernel;
DeleteObject(hParentRgn);
} void CShadowUI::ShowShadow(bool bShow)
{
m_bIsShowShadow = bShow;
} bool CShadowUI::IsShowShadow() const
{
return m_bIsShowShadow;
} bool CShadowUI::SetSize(int NewSize)
{
if(NewSize > 20 || NewSize < -20)
return false; m_nSize = (signed char)NewSize;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd));
return true;
} bool CShadowUI::SetSharpness(unsigned int NewSharpness)
{
if(NewSharpness > 20)
return false; m_nSharpness = (unsigned char)NewSharpness;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd));
return true;
} bool CShadowUI::SetDarkness(unsigned int NewDarkness)
{
if(NewDarkness > 255)
return false; m_nDarkness = (unsigned char)NewDarkness;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd));
return true;
} bool CShadowUI::SetPosition(int NewXOffset, int NewYOffset)
{
if(NewXOffset > 20 || NewXOffset < -20 ||
NewYOffset > 20 || NewYOffset < -20)
return false; m_nxOffset = (signed char)NewXOffset;
m_nyOffset = (signed char)NewYOffset;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd));
return true;
} bool CShadowUI::SetColor(COLORREF NewColor)
{
m_Color = NewColor;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd));
return true;
} bool CShadowUI::SetImage(LPCTSTR szImage)
{
if (szImage == NULL)
return false; m_bIsImageMode = true;
m_sShadowImage = szImage;
if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd)); return true;
}
bool CShadowUI::SetShadowCorner(RECT rcCorner)
{
if (rcCorner.left < 0 || rcCorner.top < 0 || rcCorner.right < 0 || rcCorner.bottom < 0)
return false; m_rcShadowCorner = rcCorner; if(m_hWnd != NULL && (SS_VISABLE & m_Status))
Update(GetParent(m_hWnd)); return true;
} } //namespace DuiLib
总结：
这个阴影使用双层窗体实现的，可以避免duilib在半透明窗体上的不足。但也由于使用双层窗体，导致窗体大小快速改变时会看出阴影改变的延迟 ，能不能接受这个延迟就看个人了，所以如果是固定大小的窗体使用阴影效果最好。具体的效果可以看我的demo。
完整的修改版的库代码和阴影的demo，可以下载我的库：点击打开链接